Desired AFR - Actual AFR

[Hilly13]

Couple of threads have perked a thought or two, regarding the TTS AFR table and let's just say open loop to keep it simple, if you have a number, say 13.2 for example, there is no guarantee that's the actual AFR is there?
Assuming that's correct then if you establish VIA other means that the 13.2 asked for in the table is actually say 13.8 just for the sake of a number, would that .6 AFR difference be the same for the other asked for ratio's in the same table and Cal? IE 13.4 asked for is actually 14?
Thanks for any thoughts.
Hilly

[Scotty]

If you ask for 13.2 and with a good sensor detect that it is actually 13.8 then you need to adjust the VE's to get the requested & actual to be the same.........

That is basically what v-tune is trying to do with the stock sensors as well but at 14.7 less the bias setting or whatever the Lambda setting is.

Just because one cell or area is .6 out does not mean that all the cells are .6 out either.

The only way to truly know is with a good sensor and an operator that knows how to use it properly...............

Set the AFR across the map to 13.2 and dial in all the VE's till the requested = actual and then set the AFR to what you want for normal riding.

[burgies08ultra]

how r u going to tune in the ve's when vtune will not work??
burgie

[Scotty]

how r u going to tune in the ve's when vtune will not work??
burgie

Well obviously not with v-tune.............Maybe a DTT Wego system which uses sensors capable of reading down at 13.2 if you are a home user.

OR

Perhaps take it to a dyno operator who has the correct equipment.

[Steve Cole]

If you ask for 13.2 and with a good sensor detect that it is actually 13.8 then you need to adjust the VE's to get the requested & actual to be the same.........

That is basically what v-tune is trying to do with the stock sensors as well but at 14.7 less the bias setting or whatever the Lambda setting is.

The Bias setting, on a HD, is the target for the ECM to hit NOT a bias to 14.7

Just because one cell or area is .6 out does not mean that all the cells are .6 out either.

The only way to truly know is with a good sensor and an operator that knows how to use it properly...............

Set the AFR across the map to 13.2 and dial in all the VE's till the requested = actual and then set the AFR to what you want for normal riding.

One thing that needs to be added to the above is that some common sense needs to come into play. If you request 13.2 (as above) and the shape of the VE tables becomes up/down over and over (cliff/valleys) throughout the range then something else is going on, as that is not how a mechanical engine is going to work. That something else is important and needs to be identified and resolved. It could come from lots of thing from a lifter pumping up, cracked exhaust, leaking sensors setup, EGR ect. If you identify and resolve it you will be able to feel it and measure the results.

[Scotty]

That is basically what v-tune is trying to do with the stock sensors as well but at 14.7 less the bias setting or whatever the Lambda setting is.

The Bias setting, on a HD, is the target for the ECM to hit NOT a bias to 14.7

That's what I said.................you should learn to read Australian a bit better. 

[Steve Cole]

What am I missing then?

You said "14.7 less the bias"

That's not correct. The CLB setting is the voltage the ECM is targeting directly.

If you run a fixed gas across the sensor it is going to generate a voltage based on that gas. If you then change the gas to a different one, it again, is just going to generate a fixed voltage, it doesn't switch voltages as some believe. The ECM drives the system richer and when it see the voltage change it then begins to drive it leaner until the voltage again changes. This is why you see the switching occur in a stock system.

[burgies08ultra]

how do u set bias on a lamba bike like a 2012 ttriglide??
burgie

[rbabos]

What am I missing then?

You said "14.7 less the bias"

That's not correct. The CLB setting is the voltage the ECM is targeting directly.

If you run a fixed gas across the sensor it is going to generate a voltage based on that gas. If you then change the gas to a different one, it again, is just going to generate a fixed voltage, it doesn't switch voltages as some believe. The ECM drives the system richer and when it see the voltage change it then begins to drive it leaner until the voltage again changes. This is why you see the switching occur in a stock system.

But isn't the switching voltage fixed for 14.7 at say 450mv and the clbs an offset or bias to alter the switching voltages in the ecm? The mid point between high mv and low mv of the wave is the target afr, isn't it?
Ron

[Scotty]

What am I missing then?

You said "14.7 less the bias"

That's not correct. The CLB setting is the voltage the ECM is targeting directly.

If you run a fixed gas across the sensor it is going to generate a voltage based on that gas. If you then change the gas to a different one, it again, is just going to generate a fixed voltage, it doesn't switch voltages as some believe. The ECM drives the system richer and when it see the voltage change it then begins to drive it leaner until the voltage again changes. This is why you see the switching occur in a stock system.

I was talking in laymans terms that any normal person using the TTS would understand.

People find EFI terminology hard enough as it is so explaining that the standard closed loop system targets 14.7 less what ever you set the BIAS at makes perfect sense to normal people who use the calculator that comes with Mastertune.

Say they want to know that the system is looking for 14.45 so they pop up your O2 calculator and they see even you have in the calculator 14.68 (14.7) and if they set the bias to 778mv the AFR should be 14.45.

So basically the stock system looks for 14.7 less whatever you set the bias to makes perfect sense.

[Scotty]

how do u set bias on a lamba bike like a 2012 ttriglide??
burgie

No bias in lambda bikes you can set the Main Lambda table to lower values which is SORT of the same as the bias in the AFR models.

[wurk_truk]

how do u set bias on a lamba bike like a 2012 ttriglide??
burgie

No bias in lambda bikes you can set the Main Lambda table to lower values which is SORT of the same as the bias in the AFR models.

Burgie, this is correct.  Here is how to look things over so you understand a bit better...  Lambda is 1.000.   So, when you have your closed loop areas like .997, .977, etc... that difference from 1.000 is the bias, just like AFR bias can be around 14.4/ 778.  See?  So when you change your closed loop lambda tables to less than that 1.000, you are 'biasing' them.

It is actually a bit different, because Lambda at 1.000 may NOT be 14.7, but this is the easiest way for ME to think about bias and lambda closed loop.

[Scotty]

how do u set bias on a lamba bike like a 2012 ttriglide??
burgie

No bias in lambda bikes you can set the Main Lambda table to lower values which is SORT of the same as the bias in the AFR models.

Burgie, this is correct.  Here is how to look things over so you understand a bit better...  Lambda is 1.000.   So, when you have your closed loop areas like .997, .977, etc... that difference from 1.000 is the bias, just like AFR bias can be around 14.4/ 778.  See?  So when you change your closed loop lambda tables to less than that 1.000, you are 'biasing' them.

It is actually a bit different, because Lambda at 1.000 may NOT be 14.7, but this is the easiest way for ME to think about bias and lambda closed loop.

Damn did you just explain that in laymans terms ?

Even I understood it 

[Steve Cole]

What am I missing then?

You said "14.7 less the bias"

That's not correct. The CLB setting is the voltage the ECM is targeting directly.

If you run a fixed gas across the sensor it is going to generate a voltage based on that gas. If you then change the gas to a different one, it again, is just going to generate a fixed voltage, it doesn't switch voltages as some believe. The ECM drives the system richer and when it see the voltage change it then begins to drive it leaner until the voltage again changes. This is why you see the switching occur in a stock system.

But isn't the switching voltage fixed for 14.7 at say 450mv and the clbs an offset or bias to alter the switching voltages in the ecm? The mid point between high mv and low mv of the wave is the target afr, isn't it?
Ron

There is NO switching voltage per say. Look at the output curve of the sensor an it gives you a voltage for a given content of O2 versus the outside O2, that's it.

When you set the CLB tables you are setting the point at which YOU want the system to be at. The ECM will drive the mixture until it gets richer than what you set and once it passes that setting it will then begin to drive the mixture leaner until it again passes YOUR set point. Now it can only do it within the range that the sensor can measure but this is why you see the O2 voltage going up and down. It's not the O2 doing it, it is the ECM doing it and the O2 reporting it.

As for the Bias it's not taken from 14.7 and the O2 Sensor Voltage Calculator has 14.68 set as the "Stoichiometeric AFR" not any bias value. Guess down under they do things different but I try to make sure people try and learn the right things. The more they get told the wrong things the more confused they get.

[Scotty]

What am I missing then?

You said "14.7 less the bias"

That's not correct. The CLB setting is the voltage the ECM is targeting directly.

If you run a fixed gas across the sensor it is going to generate a voltage based on that gas. If you then change the gas to a different one, it again, is just going to generate a fixed voltage, it doesn't switch voltages as some believe. The ECM drives the system richer and when it see the voltage change it then begins to drive it leaner until the voltage again changes. This is why you see the switching occur in a stock system.

But isn't the switching voltage fixed for 14.7 at say 450mv and the clbs an offset or bias to alter the switching voltages in the ecm? The mid point between high mv and low mv of the wave is the target afr, isn't it?
Ron

There is NO switching voltage per say. Look at the output curve of the sensor an it gives you a voltage for a given content of O2 versus the outside O2, that's it.

When you set the CLB tables you are setting the point at which YOU want the system to be at. The ECM will drive the mixture until it gets richer than what you set and once it passes that setting it will then begin to drive the mixture leaner until it again passes YOUR set point. Now it can only do it within the range that the sensor can measure but this is why you see the O2 voltage going up and down. It's not the O2 doing it, it is the ECM doing it and the O2 reporting it.

As for the Bias it's not taken from 14.7 and the O2 Sensor Voltage Calculator has 14.68 set as the "Stoichiometeric AFR" not any bias value. Guess down under they do things different but I try to make sure people try and learn the right things. The more they get told the wrong things the more confused they get.

Your saying the exact same thing ..........semantics

450mv - 14.68 AFR

778mv - 14.45 AFR

so the system is set for 14.68 when set at 450mv

OR

If i want 14.45 I set it for 778mv

So the actual AFR out the pipe is 14.45

OR

you could describe it as 14.68 - bias difference = 14.45

So the AFR is 14.68 (14.7) less the bias setting.

semantics...............still the same result

[burgies08ultra]

if the lamba  can be set at say 967 as opposed to 981, which is  what is required to do a vtune, why vtune to 981  and then change it to 967??   wont the fuel be off??
burgie

[Steve Cole]

burgies08ultra

The system has a limit that it will operate in and 0.981 it very near the limit. That is why we say to use that setting.

Scotty

You can keep going at it but it's not the same and I'm not going to continue to argue with you about it, it's not worth it.

Try this and maybe you will understand. Go to the O2 calculator in Mastertune, write down the default setting it comes up with. Then change the Stoichiometeric value to 14.45 and then <click> on the Calculate button. See what the O2 Voltage says now, it will be different!Then go look at ALL the values in the chart as they will have changed as well!

[burgies08ultra]

i vtuned to 981 and it came out good
but when i am running the bike, the oil is at about 250degrees and the engine temp in the data runs is right at 300.. sometimes over if doing 70 or more...
so i was thinking about going to 967   for crusing to cool it down.. it that not a good idea?/
burgie
rem i am running a 2012 triglide

[wolf_59]

All the arguing back and forth just makes things more confusing for those of us that just want to learn and understand, I respect the knowledge that is shared on this site but myself and others would appreciate it if someone could answer the question simply without all the high tec mumbo jumbo.
This is the way I understand it, I think   
Stoich = 1.000 lambada = 450mv no matter what fuel or octane or whatever
Stoich for gasoline is somewhere between 14.68 and 14.27 depending on the quality of the fuel where you purchase it and whateverelse comes into play
so if you do actually have gasoline with a stoich of 14.68 and you vtune with clb's set at 741 mv your commanded AFR of 14.6 would deliver 14.6
However if you have gasoline that has a stoich of 14.27 and you vtune with clb's set at 741 mv your commanded AFR of 14.6 would deliver 14.2
Is this the correct way to look at this ? 

[hrdtail78]

"14.7 less the bias setting"

Are you saying the number set in the bias is subtracted from 14.7?   I understand it as 14.6 is the switch that tells the ECM to look at the bias table and use the setting there.

[Jeffd]

i vtuned to 981 and it came out good
but when i am running the bike, the oil is at about 250degrees and the engine temp in the data runs is right at 300.. sometimes over if doing 70 or more...
so i was thinking about going to 967   for crusing to cool it down.. it that not a good idea?/
burgie
rem i am running a 2012 triglide

I wonder how rich does one have to go to actually get a decernable cooling affect?  Not so sure 250* oil temp is all that high with todays oils.

[glens]

All the arguing back and forth just makes things more confusing for those of us that just want to learn and understand, I respect the knowledge that is shared on this site but myself and others would appreciate it if someone could answer the question simply without all the high tec mumbo jumbo.
This is the way I understand it, I think   
Stoich = 1.000 lambada = 450mv no matter what fuel or octane or whatever

Yes.

Stoich for gasoline is somewhere between 14.68 and 14.27 depending on the quality of the fuel where you purchase it and whateverelse comes into play

Yes.  Probably even lower than 14.27

so if you do actually have gasoline with a stoich of 14.68 and you vtune with clb's set at 741 mv your commanded AFR of 14.6 would deliver 14.6

Nearly.  If your gasoline was stoich at 14.68, 14.6 commanded at 450 mV setpoint would deliver 14.68   If you'd specified a setpoint of 741 mV then 14.6 commanded would deliver 14.61

However if you have gasoline that has a stoich of 14.27 and you vtune with clb's set at 741 mv your commanded AFR of 14.6 would deliver 14.2
Is this the correct way to look at this ? 

So yes, this is pretty much the correct way to look at it.

This is also why "lambda" makes so much more sense because its numbers are always true.  It's not using numbers that don't mean anything except on rare occasion as is the case with "AFR" numbers.  If you consult the chart in the TTS voltage calculator you'll see that "741 mV" corresponds to "0.995 lambda".  If you command 0.995 lambda you'll get it regardless the fuel while commanding "AFR" numbers rarely gets you the numbers you'd asked for, even though the mixture will be correct regardless (because the system is really using "lambda" in the background while closed-loop, whether it or you know it).

So just use lambda all the time and all the questions disappear.  TTS should allow a toggle in the software to show lambda values in the main fuel table on the "AFR" calibrations.  How I'd set up the software would be to show the closed-loop lambda values that result from the chosen CLB values.  I realize it wouldn't be a straightforward proposition, but it'd be worlds better than fake "AFR" numbers which only serve to confuse folks.

[Hilly13]

Thanks to all that replied, got what I was after, if only the stock ECU could be fitted with 02 sensors capable of accurately measureing a broader range, that would be very helpfull

[mayor]

Couple of threads have perked a thought or two, regarding the TTS AFR table and let's just say open loop to keep it simple, if you have a number, say 13.2 for example, there is no guarantee that's the actual AFR is there?
Assuming that's correct then if you establish VIA other means that the 13.2 asked for in the table is actually say 13.8 just for the sake of a number, would that .6 AFR difference be the same for the other asked for ratio's in the same table and Cal? IE 13.4 asked for is actually 14?

I'm not sure anyone actually answered your direct question, the answer is no.  You can not assume that if one areas is off by a fixed value that all areas would be off by that same fixed value.  There are just too many variables at play.  If you are asking this in regards to how to relate open loop values, based on limited sample info (like tested wide open on one cylinder)...the answer is a definite no- there are two many variables at play.   

[wolf_59]

Thank you Glens 
So the only way to know where to set the open loop areas of the AFR after Vtune is to sample the exhaust